The invention relates in general to the field of test devices for diagnostic testing, such as rapid testing devices (e.g., point-of-care test devices and over-the-counter tests). In particular, the invention is directed to devices comprising an optical readable medium, formed by a pattern of spots of material, which may for instance encode security features.
Rapid diagnostic test (RDT) devices are devices used for quick and easy medical diagnostic tests. They typically allow results to be obtained within a few hours or less. They notably include point-of-care (POC) test devices and over-the-counter (OTC) tests.
Point-of-care (POC) test devices are known and these devices relate to point-of-care testing, also called bedside testing. Such devices allow medical diagnostic testing at or near the point of care, e.g., at the time and place of the patient care. Over-the-counter (OTC) tests are similar devices. They are, however, typically simpler than POC devices and can often be purchased in pharmacies for people to perform the test themselves, e.g., at home or away from healthcare settings and without assistance from healthcare staff.
Such test devices are typically portable, e.g., handheld devices, easy to use, low cost to manufacture, and fast. They are therefore considered an essential technology by the World Health Organization (WHO) for combatting infectious diseases, amongst others, and improving health in countries where such diseases are endemic. OTC devices are frequently used for monitoring therapy (e.g., to ensure appropriate doses of blood anticoagulant drugs), for monitoring glucose in blood, or for detecting drugs of abuse in body fluids.
The most widely used diagnostic devices are perhaps the so-called “lateral flow assays”, which rely on a stripe of cellulose along which a sample flows and reacts with reagents. Such devices are also called strip tests and are typically provided in the form of sticks to be dipped into a liquid to perform the test. If analytes are present in the sample, a colored signal appears on the stripe. Such tests are used to detect malaria, hepatitis virus, HIV, biomarkers related to heart failure, etc.
Besides diseases, test devices as contemplated herein are commonly used to detect a specific condition, such as pregnancy or ovulation.
There has been numerous reports and alerts on such tests being counterfeited or inappropriately sold. For instance, several sources have reported that counterfeited tests had been sold for diagnosing Leishmaniasis. In addition, fake pregnancy tests, fake tests for glucose monitoring and fake human immunodeficiency virus (HIV) test kits (originally designed to test for pregnancy or other conditions) have reportedly been sold, amongst other frauds.
The WHO estimates that counterfeiting of tests compromises the detection, surveillance and eradication of some diseases. This is particularly worrying for large-scale infectious diseases as the latter typically need concerted and global surveillance. The programs of prevention, treatment, detection, and eradication that are developed to combat such diseases sometimes require concerted efforts between several countries. They typically involve heterogeneous types of patients and healthcare settings (e.g., itinerant outpost vs. hospital). A task force called IMPACT (http://apps.who.int/impact/en/) has therefore been setup to provide recommendation and raise awareness on the problem of counterfeiting of medical products. This task force focuses on counterfeited drugs and gives useful recommendations on common approaches for adding security features to medical product packages.
Unfortunately, such security features are frequently breached in practice.